1 /* 2 * Device handling code 3 * Linux ethernet bridge 4 * 5 * Authors: 6 * Lennert Buytenhek <buytenh@gnu.org> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/netdevice.h> 16 #include <linux/netpoll.h> 17 #include <linux/etherdevice.h> 18 #include <linux/ethtool.h> 19 #include <linux/list.h> 20 #include <linux/netfilter_bridge.h> 21 22 #include <asm/uaccess.h> 23 #include "br_private.h" 24 25 #define COMMON_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | \ 26 NETIF_F_GSO_MASK | NETIF_F_HW_CSUM) 27 28 const struct nf_br_ops __rcu *nf_br_ops __read_mostly; 29 EXPORT_SYMBOL_GPL(nf_br_ops); 30 31 static struct lock_class_key bridge_netdev_addr_lock_key; 32 33 /* net device transmit always called with BH disabled */ 34 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) 35 { 36 struct net_bridge *br = netdev_priv(dev); 37 const unsigned char *dest = skb->data; 38 struct net_bridge_fdb_entry *dst; 39 struct net_bridge_mdb_entry *mdst; 40 struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats); 41 const struct nf_br_ops *nf_ops; 42 u16 vid = 0; 43 44 rcu_read_lock(); 45 nf_ops = rcu_dereference(nf_br_ops); 46 if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) { 47 rcu_read_unlock(); 48 return NETDEV_TX_OK; 49 } 50 51 u64_stats_update_begin(&brstats->syncp); 52 brstats->tx_packets++; 53 brstats->tx_bytes += skb->len; 54 u64_stats_update_end(&brstats->syncp); 55 56 BR_INPUT_SKB_CB(skb)->brdev = dev; 57 58 skb_reset_mac_header(skb); 59 skb_pull(skb, ETH_HLEN); 60 61 if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid)) 62 goto out; 63 64 if (is_broadcast_ether_addr(dest)) 65 br_flood_deliver(br, skb, false); 66 else if (is_multicast_ether_addr(dest)) { 67 if (unlikely(netpoll_tx_running(dev))) { 68 br_flood_deliver(br, skb, false); 69 goto out; 70 } 71 if (br_multicast_rcv(br, NULL, skb, vid)) { 72 kfree_skb(skb); 73 goto out; 74 } 75 76 mdst = br_mdb_get(br, skb, vid); 77 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && 78 br_multicast_querier_exists(br, eth_hdr(skb))) 79 br_multicast_deliver(mdst, skb); 80 else 81 br_flood_deliver(br, skb, false); 82 } else if ((dst = __br_fdb_get(br, dest, vid)) != NULL) 83 br_deliver(dst->dst, skb); 84 else 85 br_flood_deliver(br, skb, true); 86 87 out: 88 rcu_read_unlock(); 89 return NETDEV_TX_OK; 90 } 91 92 static void br_set_lockdep_class(struct net_device *dev) 93 { 94 lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key); 95 } 96 97 static int br_dev_init(struct net_device *dev) 98 { 99 struct net_bridge *br = netdev_priv(dev); 100 int err; 101 102 br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 103 if (!br->stats) 104 return -ENOMEM; 105 106 err = br_vlan_init(br); 107 if (err) 108 free_percpu(br->stats); 109 br_set_lockdep_class(dev); 110 111 return err; 112 } 113 114 static int br_dev_open(struct net_device *dev) 115 { 116 struct net_bridge *br = netdev_priv(dev); 117 118 netdev_update_features(dev); 119 netif_start_queue(dev); 120 br_stp_enable_bridge(br); 121 br_multicast_open(br); 122 123 return 0; 124 } 125 126 static void br_dev_set_multicast_list(struct net_device *dev) 127 { 128 } 129 130 static void br_dev_change_rx_flags(struct net_device *dev, int change) 131 { 132 if (change & IFF_PROMISC) 133 br_manage_promisc(netdev_priv(dev)); 134 } 135 136 static int br_dev_stop(struct net_device *dev) 137 { 138 struct net_bridge *br = netdev_priv(dev); 139 140 br_stp_disable_bridge(br); 141 br_multicast_stop(br); 142 143 netif_stop_queue(dev); 144 145 return 0; 146 } 147 148 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev, 149 struct rtnl_link_stats64 *stats) 150 { 151 struct net_bridge *br = netdev_priv(dev); 152 struct pcpu_sw_netstats tmp, sum = { 0 }; 153 unsigned int cpu; 154 155 for_each_possible_cpu(cpu) { 156 unsigned int start; 157 const struct pcpu_sw_netstats *bstats 158 = per_cpu_ptr(br->stats, cpu); 159 do { 160 start = u64_stats_fetch_begin_irq(&bstats->syncp); 161 memcpy(&tmp, bstats, sizeof(tmp)); 162 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start)); 163 sum.tx_bytes += tmp.tx_bytes; 164 sum.tx_packets += tmp.tx_packets; 165 sum.rx_bytes += tmp.rx_bytes; 166 sum.rx_packets += tmp.rx_packets; 167 } 168 169 stats->tx_bytes = sum.tx_bytes; 170 stats->tx_packets = sum.tx_packets; 171 stats->rx_bytes = sum.rx_bytes; 172 stats->rx_packets = sum.rx_packets; 173 174 return stats; 175 } 176 177 static int br_change_mtu(struct net_device *dev, int new_mtu) 178 { 179 struct net_bridge *br = netdev_priv(dev); 180 if (new_mtu < 68 || new_mtu > br_min_mtu(br)) 181 return -EINVAL; 182 183 dev->mtu = new_mtu; 184 185 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 186 /* remember the MTU in the rtable for PMTU */ 187 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 188 #endif 189 190 return 0; 191 } 192 193 /* Allow setting mac address to any valid ethernet address. */ 194 static int br_set_mac_address(struct net_device *dev, void *p) 195 { 196 struct net_bridge *br = netdev_priv(dev); 197 struct sockaddr *addr = p; 198 199 if (!is_valid_ether_addr(addr->sa_data)) 200 return -EADDRNOTAVAIL; 201 202 spin_lock_bh(&br->lock); 203 if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) { 204 /* Mac address will be changed in br_stp_change_bridge_id(). */ 205 br_stp_change_bridge_id(br, addr->sa_data); 206 } 207 spin_unlock_bh(&br->lock); 208 209 return 0; 210 } 211 212 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 213 { 214 strlcpy(info->driver, "bridge", sizeof(info->driver)); 215 strlcpy(info->version, BR_VERSION, sizeof(info->version)); 216 strlcpy(info->fw_version, "N/A", sizeof(info->fw_version)); 217 strlcpy(info->bus_info, "N/A", sizeof(info->bus_info)); 218 } 219 220 static netdev_features_t br_fix_features(struct net_device *dev, 221 netdev_features_t features) 222 { 223 struct net_bridge *br = netdev_priv(dev); 224 225 return br_features_recompute(br, features); 226 } 227 228 #ifdef CONFIG_NET_POLL_CONTROLLER 229 static void br_poll_controller(struct net_device *br_dev) 230 { 231 } 232 233 static void br_netpoll_cleanup(struct net_device *dev) 234 { 235 struct net_bridge *br = netdev_priv(dev); 236 struct net_bridge_port *p; 237 238 list_for_each_entry(p, &br->port_list, list) 239 br_netpoll_disable(p); 240 } 241 242 static int __br_netpoll_enable(struct net_bridge_port *p) 243 { 244 struct netpoll *np; 245 int err; 246 247 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 248 if (!np) 249 return -ENOMEM; 250 251 err = __netpoll_setup(np, p->dev); 252 if (err) { 253 kfree(np); 254 return err; 255 } 256 257 p->np = np; 258 return err; 259 } 260 261 int br_netpoll_enable(struct net_bridge_port *p) 262 { 263 if (!p->br->dev->npinfo) 264 return 0; 265 266 return __br_netpoll_enable(p); 267 } 268 269 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 270 { 271 struct net_bridge *br = netdev_priv(dev); 272 struct net_bridge_port *p; 273 int err = 0; 274 275 list_for_each_entry(p, &br->port_list, list) { 276 if (!p->dev) 277 continue; 278 err = __br_netpoll_enable(p); 279 if (err) 280 goto fail; 281 } 282 283 out: 284 return err; 285 286 fail: 287 br_netpoll_cleanup(dev); 288 goto out; 289 } 290 291 void br_netpoll_disable(struct net_bridge_port *p) 292 { 293 struct netpoll *np = p->np; 294 295 if (!np) 296 return; 297 298 p->np = NULL; 299 300 __netpoll_free_async(np); 301 } 302 303 #endif 304 305 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev) 306 307 { 308 struct net_bridge *br = netdev_priv(dev); 309 310 return br_add_if(br, slave_dev); 311 } 312 313 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 314 { 315 struct net_bridge *br = netdev_priv(dev); 316 317 return br_del_if(br, slave_dev); 318 } 319 320 static const struct ethtool_ops br_ethtool_ops = { 321 .get_drvinfo = br_getinfo, 322 .get_link = ethtool_op_get_link, 323 }; 324 325 static const struct net_device_ops br_netdev_ops = { 326 .ndo_open = br_dev_open, 327 .ndo_stop = br_dev_stop, 328 .ndo_init = br_dev_init, 329 .ndo_start_xmit = br_dev_xmit, 330 .ndo_get_stats64 = br_get_stats64, 331 .ndo_set_mac_address = br_set_mac_address, 332 .ndo_set_rx_mode = br_dev_set_multicast_list, 333 .ndo_change_rx_flags = br_dev_change_rx_flags, 334 .ndo_change_mtu = br_change_mtu, 335 .ndo_do_ioctl = br_dev_ioctl, 336 #ifdef CONFIG_NET_POLL_CONTROLLER 337 .ndo_netpoll_setup = br_netpoll_setup, 338 .ndo_netpoll_cleanup = br_netpoll_cleanup, 339 .ndo_poll_controller = br_poll_controller, 340 #endif 341 .ndo_add_slave = br_add_slave, 342 .ndo_del_slave = br_del_slave, 343 .ndo_fix_features = br_fix_features, 344 .ndo_fdb_add = br_fdb_add, 345 .ndo_fdb_del = br_fdb_delete, 346 .ndo_fdb_dump = br_fdb_dump, 347 .ndo_bridge_getlink = br_getlink, 348 .ndo_bridge_setlink = br_setlink, 349 .ndo_bridge_dellink = br_dellink, 350 .ndo_features_check = passthru_features_check, 351 }; 352 353 static void br_dev_free(struct net_device *dev) 354 { 355 struct net_bridge *br = netdev_priv(dev); 356 357 free_percpu(br->stats); 358 free_netdev(dev); 359 } 360 361 static struct device_type br_type = { 362 .name = "bridge", 363 }; 364 365 void br_dev_setup(struct net_device *dev) 366 { 367 struct net_bridge *br = netdev_priv(dev); 368 369 eth_hw_addr_random(dev); 370 ether_setup(dev); 371 372 dev->netdev_ops = &br_netdev_ops; 373 dev->destructor = br_dev_free; 374 dev->ethtool_ops = &br_ethtool_ops; 375 SET_NETDEV_DEVTYPE(dev, &br_type); 376 dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE; 377 378 dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL | 379 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX; 380 dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX | 381 NETIF_F_HW_VLAN_STAG_TX; 382 dev->vlan_features = COMMON_FEATURES; 383 384 br->dev = dev; 385 spin_lock_init(&br->lock); 386 INIT_LIST_HEAD(&br->port_list); 387 spin_lock_init(&br->hash_lock); 388 389 br->bridge_id.prio[0] = 0x80; 390 br->bridge_id.prio[1] = 0x00; 391 392 ether_addr_copy(br->group_addr, eth_reserved_addr_base); 393 394 br->stp_enabled = BR_NO_STP; 395 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 396 br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT; 397 398 br->designated_root = br->bridge_id; 399 br->bridge_max_age = br->max_age = 20 * HZ; 400 br->bridge_hello_time = br->hello_time = 2 * HZ; 401 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 402 br->ageing_time = BR_DEFAULT_AGEING_TIME; 403 404 br_netfilter_rtable_init(br); 405 br_stp_timer_init(br); 406 br_multicast_init(br); 407 } 408